Invisalign (or systems like it) are mostly a crock, and waaaay overpriced. There are very few people who can actually have successful treatment using this system. If you are really, really keen to look into it, then I would suggest that you see an orthodontist who does it as a small part of his/her practice. If you see someone who ONLY does Invisalign they will of course tell you that they can do it, even if it's not the best option for you.

It can only be successful for people with mild crowding, and very mild (or none) bite issues. And even then, using full appliances (braces) will likely be faster.